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By Douglas J. Uhren, Gary W. Gilbert

This paper describes the risk elements associated with difficult glacial geology, including boulders, heavy groundwater inflow, and potential running soils all coupled with a potentially corrosive service environment. The matrix workshop for the 168-inchfinished diameter sanitary sewer interceptor tunnel in Columbus, Ohio is assembled with the Design Team and the Owner’s design, operations, and fiscal staff. Corrosion protection alternatives are compared against cost and non-cost parameters with relative risk and weighting factors assigned. The Owner working in cooperation with the Design Team uses the matrix workshop to se

Jan 1, 2001

By W. G. Davenport

Smelting oxidizes Cu-Fe-S concentrate to matte. Converting oxidizes this matte to metallic copper. Smelting and converting are, therefore, part of the same oxidation process. It would seem natural, then, that smelting and converting should be combined to produce metallic copper in one step. This would: (a) maximize S02 capture by restricting S02 emission to a single, continuous source (b) minimize industrial oxygen and fuel requirements (c) minimize cost. This chapter discusses one step, direct-to-copper flash smelting as it is practiced in 2000. It then uses. the matrices of this book to determine: (a) the industrial oxygen and oil requirements of direct-to copper flash smelting (b) the distribution of Cu between metal and slag during direct-to-copper flash smelting. It concludes that direct-to-copper flash smelting: (a) captures?S02 efficiently from its single continuous stream of SO2 off gas (b) minimizes oxygen/oil consumption but: (c) sends -114 of its Cu-in-feed to slag.

Jan 1, 2001

By Christopher M. Kenney

Augered-cast-in-place (ACIP) piles have been utilized on commercial projects throughout many parts of the country for years, but are only beginning to be scrutinized for use on major infrastructure projects and other critical structures in some regions. Numerous engineers are aware that ACIP piles are an economical foundation alternative, and many technical papers have been presented that provide reliable methods of estimating ACIP pile load capacity. However, designers may not yet appreciate that the load-settlement behavior of ACIP piles is very similar to that of drilled shafts. This paper analyzes ACIP pile case histories from throughout the country and demonstrates that ACIP pile settlement under applied load is consistent, predictable, and very similar to the documented behavior of drilled shafts. This paper also presents a simple but accurate method of estimating ACIP pile settlement at the design load, and illustrates the need to estimate the equivalent diameter of the as-built ACIP pile when estimating pile behavior. Finally, this paper presents back-calculated values of the drained elastic modulus from the ACIP pile case histories that may be useful to those using more sophisticated methods of estimating ACIP pile settlement.

Jan 1, 2001

This paper describes the experiences with the application of the Coal Mining Roof Rating (CMRR) System to South African strata conditions. Roof classification studies using the CMRR system were undertaken as part of a SIMRAC investigation into falls of ground in South Mean collieries. Colliery roof rating exercises were undertaking in a range of geotechnical conditions from shallow level coal seams under flat topography to workings with cover depths of greater than 300m A comparison is made between the CMRR and other Rock Mass Rating systems used to classify different roof geotechnical conditions. The need for geological discontinuity orientation, blasting and rockmass stress adjustments to the CMRR is discussed. The effects of acid mine water on strata weatherability and the need to incorporate immersion tests using acid mine water are also detailed. In addition limited correlation is given between CMRR values and other geotechnical factors such as joint trace length, joint shear strength, joint orientation, weatherability and roof damage due to horizontal stress. Taking cognizance of these observations, a concept of stress induced roof damage triggering is discussed.

Jan 1, 2001

By Bob Rautenberg, Luminita Calin

The Tunnel and Reservoir Plan (TARP), commonly known as the Deep Tunnel Project, was developed by the Metropolitan Water Reclamation District of Greater Chicago as a two-phase solution to the problem of waterway pollution and basement flooding due to sewer system backups created by the combined sewer overflows. With only one contract left before completion of the Phase I tunnels—the 12.4 km(7.7 mi.) long Little Calumet leg—the pollution control phase of the 175.7 km(109.2 mi.) long system will be 93% complete, once the Torrence Avenue tunnel project comes to an end. This paper describes the Torrence Avenue tunnel project, currently under construction by the joint venture of Kenny (Sponsor) / Kiewit / Shea. Mining of the10.4 km (34,151 feet) long and 8.3 m (27'-4") diameter mainline tunnel was completed in a record thirty-one-weeks period and the concrete lining is nearing completion. Details on the complete muck handling system, numerous mining and concrete lining records will be given.

Jan 1, 2001

By Lance Helwirg

New high and low double outfall bridge structures for a juvenile fish bypass system have been constructed on the Washington Shore approximately two miles downstream from the Bonneville Dam on the Columbia River. The high and low outfalls each extend approximately 400 feet into the river from the Washington shore and are designed to release juvenile salmon into the river at above-water discharge elevations for improved survival rates. The two outfall structures include post-tensioned concrete double box flume girders approximately 7 feet high by 13 feet wide, which will be submerged in river flows as high as 15 feet per second. Each of the 6 offshore foundation piers is composed of a single 10-foot diameter reinforced concrete drilled shaft with a permanent steel casing embedded into the river bottom approximately 100 feet. Challenging outfall design conditions included designing the entire structures to be submerged for long periods of time in 15-feet-per-second river water flow with a 60-foot cantilever at the end of each outfall, and with the superstructure 70 to 80 feet above the river bottom. Figures 1-1,1-2, and 1-3 show the high and low outfall structure overhead photos and elevation view.

Jan 1, 2001

By Tracy Brettmann

? Hollow Stem Auger ? Drill Bits ? Leads/Torque Arm ? Hydraulic Gearbox ? Hydraulic Power Unit ? Grout Pump ? Crawler Crane

Jan 1, 2001

By M. H. Pelkki, R. J. Sweigard, P. W. Conrad, J. M. Ringe, D. H. Graves

Research has shown that excessive soil compaction is detrimental to the establishment of trees in reclaimed soils. Dry bulk density and penetration resistance are two soil parameters that can be used to indicate the level of compaction in reclaimed soils. It is believed that reclamation practices which minimize soil compaction will produce better results when forestland is the intended post-mining use. The University of Kentucky has developed reforestation test cells on reclaimed soils at a surface mine in eastern Kentucky to test this hypothesis. Each test cell has been planted with various species of trees, and since 1997, data have been collected at these test cells for soil average dry bulk density, average penetration resistance, average depth to refusal, and average survival rate of trees. These data have been correlated to determine the relationship between soil compaction and tree survival rate. It is believed that the two soil compaction parameters may ultimately be used to predict tree survival rates on reclaimed surface mined lands.

Jan 1, 2001

By T. O. Hagan

A simulated rockburst experiment was conducted underground at a deep level gold mine. This was done by means of a large explosion detonated in solid rock close to a tunnel sidewall. The resultant shake-out damage is typical of that associated with a small seismic event in close proximity to a tunnel that is subjected to the estimated field stress, as in this case, of 50 MPa. The experiment involved: ?the design of a blast to mimic a seismic source ?seismic monitoring using a dense seismic array ?high speed video filming ?a study of rock mass conditions (fractures, joints, rock strength etc.) before and after the simulation using mapping and ground penetrating radar ?special investigations to evaluate the mechanism and the magnitude of the damage ?a study of support behaviour under excessive dynamic loading.

Jan 1, 2001

By Douglas Anderson

Even though there is always a feeling of anticipation before a blast is detonated, most blasts are part of a day’s work. Once in a while there is an event that impresses even the most jaded blaster. Few blasts have had the impact of the Kingdome implosion in March of this year. Fortunately for both the Seattle area and the explosives community, the “impact” of the implosion was far less than many local residents had feared. This outcome, of course, was not by chance, but the result of careful planning and design. An urban implosion requires a mix of engineering, logistics, and public relations. Unique challenges on this project tested the resourcefulness of the entire team.

Jan 1, 2001

By J. W. Craven, M. Katom, K. M. McCaffery

At Ok Tedi, ore type and SAG feed size distribution vary widely and frequently. This makes control of the SAG mills by application of the power/pressure relationship difficult. Power logic has traditionally been conservative due to power spikes associated with rapid size distribution changes. A new expert system was installed in early 2000. The system incorporates multiple state fuzzy logic to deal with frequent and radical ore type and size variations, along with monitoring of motor temperatures. A short term power spike no longer warrants immediate radical action. This has resulted in increased mill throughput and improved circuit stability.

Jan 1, 2001

By H. Y. Sohn, R. D. Hagni, M. K. Kojo

Reflected light microscopy was used to study the mineralogy and textures of experimental reactions of a nickel concentrate with a slag. Such an interaction is an important step in the bath smelting of nickel sulfide concentrate. Concentrate particles in the central portions of the pellets are rounded and develop vermicular SO2 gas porosity. In the outer portions of the pellets, the original minerals of the concentrate, pyrrhotite, pentlandite, pyrite, chalcopyrite, and violarite have agglomerated and reacted to form two intergrown phases: 1) pyrrhotite solid solution (Fe0.75Ni0.18Cu0.01S) and pentlandite solid solution (Fe0.58Ni0.51Cu0.03S). Magnetite formed euhedral crystals, skeletal crystals, and dendrites at the margins of the matte. Prismatic ferrohypersthene and octahedral Mg-Al-Fe spinel crystals and dendrites are present in the glassy slag.

Jan 1, 2001

By Robert A. Medower

This paper will review the operational benefits of applying contemporary control technology to balance the blast to a cupola. Reported benefits from existing installations include reduced channelling, higher pour temperature, reduced oxygen consumption, lower coke consumption & reduced emissions.

Jan 1, 2001

By Javaid M. Alvi

This paper is an attempt to outline the emergence of Augered Cast-ln-Place piles as one of the more economical types of foundation for supporting high-rise buildings and heavily loaded structures recently constructed in the flood plains in and around the Greater Pittsburgh area. To understand the process of selecting foundation types, it is important to understand the general geology of the area and past construction activities that have taken place in the flood plains, especially along the riverbanks, during the last century. The first part of this paper presents a brief description of the general geology of the area; the second part of the paper concentrates on the historical evolution of the use of deep foundations and selected case histories; and the last part presents the results of load tests on large diameter Augered Tremie Concrete (ATC) Piles placed in sandy alluvium which suggests a much larger load-carrying capacity of these piles and also provides an insight into their future application. 2.0 GENERAL GEOLOGY 2.1 Soil Overburden Most of the high rise buildings in the Central Business District as well as along the North Shore and South Side of Pittsburgh are situated in the flood plain at the confluence of the Allegheny River and the Monongahela River where their combined flow forms the Ohio River. The flood plain consists of unconsolidated deposits of Quaternary age that overlie the bedrock of Pennsylvanian age. These deposits are called alluvium or valley fill, and include moderately to poorly sorted clay, silt, sand, gravel and some boulders. Their thickness varies from zero at the edges of the valley to about 80 feet towards the rivers (Figure 1).

Jan 1, 2001

By D J. Woodward, A B. Christie, S A. Henrys

Low-level aeromagnetic data available in digital form have been combined to produce a new 1:100 000 scale map of total force anomalies of the Coromandel region, New Zealand. The map incorporates data from 13 surveys flown between 1977 and 1990 and shows the regional magnetic pattern as well as more detailed localised anomalies. In addition to magnetic anomalies, the map also depicts data to aid interpretation, including small-scale maps of topography, geology, magnetic intensity gradient and apparent magnetisation. The primary magnetic anomalies of the Coromandel region are associated with Late Miocene and Pliocene volcanic rocks, but have been locally modified by intense hydrothermal alteration caused by geothermal activity. Epithermal gold-silver and porphyry copper deposits are associated with zones of hydrothermal alteration. The map of magnetic anomalies can be used as an aid to mineral exploration and the interpretation of the processes that control the distribution of mineral deposits in the region.

Jan 1, 2001

By W. G. Davenport

The remainder of this book develops and uses mass and heat balances to describe steady"state flash smelting. Its objectives are to: a) describe the many ways a flash furnace operator can produce specified products, e,g. 65% eu matte, 35% SiOz slag, 1500 K (b) determine the oxygen, air, flux and hydrocarbon fuel requirements of each method (c) show how the flash furnace can be controlled to give specified products with varying feed compositions (d) suggest how the flash furnace operator can maximize profitability while producing specified products. This chapter develops the basiC heat and mass balance equations of steady-state ?flash smelting. It then adapts the equations to industrial feed materials .and products. Lastly it determines the amounts of oxygen and flux needed to produce molten matte and 35% SiOz slag from chalcopyrite concentrate in an Inco oxygen flash furnace,

Jan 1, 2001

By L. A. Cramer

Platinum metal was first utilized by the Inca civilization in South America where it was found in alluvial deposits along the San Juan and Atrato rivers that lie between the Andean mountain range in Colombia and the Pacific Ocean. The nuggets found in these rivers average between 77% and 86%platinum, 7%?8% iron and small amounts of copper, gold and other Platinum Group Metals (PGMs). The Incas often alloyed platinum with copper to increase its workability and fabricated various ornaments from it.

Jan 1, 2001

By Davorin Kolic, Harald Wagner

Conventional ground support in accordance with latest state-of-the-art considers proper preparation of geotechnical investigation, structural design, observation during construction and fair risk sharing documents. Depending on the ground, there are different means and methods, reflecting different experiences. The paper is presenting ground support concepts, as mostly used in Europe during the past three decades. It discusses the use of anchors as well as the use of steel arches respectively combinations. It also discusses different applications of plain shotcrete, respectively fibre reinforced shotcrete. As excavation sequence is a major input to create the ground arch, the paper discusses also criteria to create closed ring conditions. Finally deformation criteria will be presented with case histories in order to control stability of the structure.

Jan 1, 2001

By Stavros A. Argyropoulos, Henry H. Hu

"The assimilation of exothermic additions in liquid metals exhibit an array of unique coupled heat, mass and momentum transport phenomena. These phenomena are further complicated by the presence of a moving boundary.This paper describes a) A mathematical model which simulates the complex phenomena, and b) An extensive verification of the mathematical model. The SIMPLER algorithm was employed to solve numerically the pertinent partial differential equations. The computational results indicated that the exothermic heat of mixing led to a rapid increase in temperature around the moving boundary, which produced an enhanced convective flow in the liquid phase. The intensification of fluid flow around the moving boundary resulted in an acceleration of the melting process.Verification of the model was carried out in two contexts. The first was, in a low temperature physical model consisting of ice immersion in different sulfuric acid solutions. In this physical model, both temperature and velocity measurements were carried out. The model results were compared with experimental measurements and they were found to be in excellent agreement. The second context employed high temperatures, involving the assimilation of silicon in high carbon liquid iron. The model was also applied to predict fluid flow, heat and mass transfer for these high temperature experiments and a good agreement was obtained.In addition new dimensionless heat transfer correlations that quantify these complex phenomena will be presented."

Jan 1, 2001

By Katsukiyo Marukawa, Manabu Iguchi, Sigeta Hara, Shinichiro Yokoya, Sigeo Takagi

"A numerical analysis and water model study of the mold region of a continuous casting apparatus was performed with a novel injection concept using swirling flow in the pouring tube, to control the heat and mass transfer in the continuous casting mold.As a result, the following results were found:1) By changing swirl strength, it is easy to control the flow pattern as well as the direction of the flow.2) Uniform velocity distribution can be obtained within a very short distance from the outlet of the nozzle.3) Heat and mass transfer near the meniscus can be remarkably activated compared with a conventional straight type immersion nozzle without swirl.4) Swirl helps the superheat in the melt dissipate.S) Penetration depth of nozzle outlet flow is decreased remarkably by the application of swirling.6) For the case without swirl, the peak of the flow moves near the mold-wall with flowing down from the outlet of the nozzle due to the Coanda-effect. On the other hand, peak of the flow moves near the mold axis with flowing down from the nozzle-outlet within considerable short distance, namely axi-symmetric velocity distribution can be obtained within very short distance from the nozzle-outlet.Those findings mentioned above are very useful to control the flow pattern in the billet and bloom continuous casters."

Jan 1, 2001